Buoyant automatic cleaners for spas and other water-containing vessels

ABSTRACT

Autonomous, mobile cleaners for water-containing vessels such as swimming pools and spas are detailed. The cleaners are especially useful for cleaning spas, although they may function adequately in connection with certain other vessels as well. They may be designed and constructed in particular to avoid high centering so as not to become stuck when encountering obstacles within the spas or other vessels.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority to U.S. ProvisionalPatent Application Ser. No. 62/383,777, filed Sep. 6, 2016, and havingthe same title as appears above, the entire contents of whichapplication are hereby incorporated herein by this reference.

FIELD OF THE INVENTION

This invention relates to autonomous, mobile cleaners forwater-containing vessels such as swimming pools and spas and moreparticularly, although not necessarily exclusively, to buoyant cleanersof vessels having complex interior geometries such as spas.

BACKGROUND OF THE INVENTION

Numerous automatic pool cleaners exist. Typically these cleaners travelalong bottom surfaces (floors) of pools, vacuuming debris-laden waterthrough filters which capture the debris. Some cleaners also areconfigured to climb side surfaces (walls) of pools in an effort tocapture particulate matter either attached to the walls or suspended inpool water adjacent the walls. Because intended to clean floors of poolsand remain partly or wholly submerged in water while in use, thesecleaners are designed and weighted so as not to be buoyant in water.This is especially true for electrically-powered pool cleaners, whoseon-board motors, pumps, and (in some cases) batteries have substantialweight. Such cleaners are difficult to retrieve from pool floors whentheir batteries discharge, however, and may require additionalmechanical or electrical mechanisms for maneuvering when their movementis impeded by, for example, complex geometries within pools.

U.S. Pat. No. 4,154,680 to Sommer, whose entire contents areincorporated herein by this reference, describes one suchelectrically-powered pool cleaner. In an effort to make it easier toretrieve from a pool, the cleaner includes “diving cells” mounted to itschassis for purposes of raising and lowering the chassis in the pool.Attached to the diving cells is an elongated air hose extending upward“beyond the water surface.” See Sommer, col. 2, ll. 40-47. Abidirectional on-board pump is used to flood the diving cells with waterto ensure the cleaner submerges in the pool water for cleaning purposes.Changing rotational direction “causes the diving cells to fill with airand the [cleaner] to rise to the surface” of the pool for retrieval. Seeid., col. 3, ll. 28-39 (numeral omitted).

Absent from existing automatic cleaners is any natural buoyancy of theirbodies or chassis. If a cleaner were made with positive buoyancy, nodiving cells and elongated air hose would be needed to raise the cleanerto the water surface. Instead, the cleaner would naturally float to thesurface—unless and until subjected to sufficient down force tocounteract the buoyancy.

European Patent Application No. 1980687 of Hui, whose entire contentsare incorporated herein by this reference, details anotherelectrically-powered pool cleaner with negative buoyancy. Alsoconsistent with conventional designs, the bottom surface of the cleanerof the Hui application is flat, forming a plane parallel to the poolsurface to be cleaned. See Hui, col. 4, ll. 41-44. The planar bottomsurface, moreover, is positioned “close to [the] swimming pool floor” soas to improve water intake into the cleaner. This combination of planarbottom surface both parallel, and closely positioned, to theto-be-cleaned surface subjects the cleaner of the Hui application torisk of becoming stuck (e.g. high-centering) when the cleaner encountersobstacles protruding upward from the surface. This risk ofhigh-centering is further increased by the fact that water is outputfrom the cleaner in a direction perpendicular to the surface to becleaned, hence providing no forward motive force.

SUMMARY OF THE INVENTION

The present invention seeks to resolve these and other issues associatedwith conventional automatic cleaners. It also attempts to provideautomatic cleaners well adapted to clean spas and other generallysmaller water-containing vessels having complex interior geometries.Autonomous cleaning devices consistent with the present invention thusinclude numerous features not present in existing automatic poolcleaners.

As one such example, the present innovative cleaners may have positivebuoyancy. Accordingly, they are capable of naturally floating to thewater surface when not subjected to countervailing forces. Versions ofthe cleaner may include a motor and possibly an associated pump as wellas a battery for powering the motor. These versions also could include aturbine, propeller, or other means for creating down force when themotor is operating.

In use, therefore, operation of the motor would create down forcecounteracting the positive buoyancy of the cleaner. This would cause thecleaner to remain submerged within a vessel so as to perform itscleaning functions in conventional ways. However, when the batterydischarges, operation of the motor will cease, and the cleaner willfloat to the vessel surface for retrieval. Similarly, if the cleaner isprogrammed or configured to withdraw power to the motor at a particulartime (e.g. end of a cleaning cycle) or upon occurrence of a particularevent (e.g. movement of the submerged cleaner is impeded), the cleaneragain will float to the surface.

Moreover, some versions of the cleaner may disconnect the motor from thepower source either at designated intervals or randomly and subsequentlyreconnect the two. In this manner, the cleaner will, from time to time,float to (or toward) the vessel surface and, in effect, repositionitself within the vessel before submerging or lowering again when themotor recommences operation. Hence, the repositioning may allow forelevational changes by the cleaner (useful for “climbing” steps orbenches), moving up over floor obstacles, changing directions ofmovement, or simple movement so as to increase cleaning coverage. Theprocess often avoids the cleaner becoming stuck in particular regions ofa vessel or, if a cleaner has become stuck, provides opportunities torelease the cleaner from the obstacle. It thus makes the cleanerespecially useful for operating in spas, which often have complexinterior geometries with, for example, sharp angles, benches, steps, jetnozzles, air nozzles, water outlets, drains, foot massage features, etc.

Accordingly, positive-buoyancy cleaners of the present invention permitcleaning of vessels such as swimming pools and spas while facilitatingretrieval of the cleaners and reducing risk of their travel beingimpeded for long periods of time. Because no elongated air hose,electrical cord, or cable is needed by any of the inventive cleaners, norisk of tangling or sticking of such hose, cord, or cable exists.Similarly, because no back-up valve, pressurized back-up jet, or othermechanical or electrical mechanism is needed to effect repositioning (orchange of movement direction) of the cleaners, they may be simpler, andless prone to component failure, than conventional devices.

Furthermore, at least some versions of the present automatic cleanerscontemplate using at least one propeller to generate down force. Thepropeller may provide torque, rotating the cleaner as it descends to thefloor of a vessel. This usually will cause the cleaner to face in adifferent direction than it did when it ascended, further reducing thepossibility of the cleaner remaining in, or immediately returning to,the same floor location for cleaning. Yet other versions may angle thepropeller output away from the vertical, providing lateral movement soas to “push” the cleaners away from positions in which they might stick.Alternatively or additionally, buoyancy of the cleaners may beasymmetric (e.g. one side may be made more buoyant in water than anotherside) for purposes of displacing the cleaners laterally if desired.

Cleaning apparatus of the present invention also may have a bottomsurface that normally is angled to, rather than parallel to,to-be-cleaned surfaces of a pool or spa. In side view from nominal frontto nominal rear of the cleaner, the bottom surface may slope away fromthe to-be-cleaned surface. Consequently, an axle for rear motiveelements may be further from the to-be-cleaned surface than any axle forfront motive elements. By driving these larger-diameter rear motiveelements as well as the front motive elements, the cleaner is lesslikely to become stuck on obstacles protruding upward from theto-be-cleaned surface.

Although the rear motive elements typically (but not necessarily) willbe wheels, the inventive cleaner also may lack both front wheels and anyside tracks. Instead, the front motive element preferably is a rotatingscrub brush (or “scrubber”). Because the scrubber may too be driven, itcan function both to scrub the to-be-cleaned surface and to move thecleaner within the vessel. Furthermore, the scrubber advantageously maybe driven at a speed greater than that of the rear motive elements, withone preferred drive speed ratio being approximately 1.3:1.

Additional features of these novel cleaners include positioning thescrubber inside the water inlet and incorporating sensors designed todetermine whether a cleaner is, or is not, submerged. Effectivelycausing the scrubber to form a wall or boundary of the water inletmaximizes the bottom surface which may be angled without sacrificingsuction power available for debris pick-up. It also allows the scrubberitself to facilitate debris intake, as the scrubber not only agitatesdebris into suspension, but also helps accelerate and “paddle” thedebris mechanically into the inlet. Including water sensors and linkingthem to motor function prevents the cleaners from operating when out ofwater. A presently-preferred water sensor comprises two metal posts;when the cleaner is in water, conductivity will be sufficiently high soas to close a circuit including the metal posts, establishing that motorfunction may begin.

At least one thrust jet of the present cleaner may exhaust watertherefrom. Unlike the outlet of the Hui cleaner, that of the presentinvention does not cause water to exhaust perpendicular to theto-be-cleaned surface. Instead, the thrust jet exhausts water at anacute angle to both (1) the to-be cleaned surface and (2) the slopedbottom surface of the cleaner. In one embodiment of the invention, thethrust jet may exhaust water at an angle of approximately sixty degrees(˜60°) to the to-be-cleaned surface so as to provide substantial downforce to counteract the positive buoyancy of the cleaner while alsosupplying some forward motive force. Assuming a nominal slope of twentydegrees (20°) for the bottom surface yields an angle of approximatelyforty (˜40°) between the thrust output direction and the bottom surface.

Because the water inlet of the cleaner may be positioned immediatelybehind (and adjacent) its front motive element, the cleaner is likely toingest air, particularly when it is scrubbing the waterline of thevessel and thus not fully submerged. Air ingestion is an especialproblem for many existing pool cleaners, as the ingested air can becometrapped within the cleaners and cause them to float, a conditionprecluding further cleaning and possibly causing their pump motors torun dry. Unlike existing cleaners, however, those of the presentinvention may include domed debris collection chambers configured tofacilitate handling of ingested air. Although the ingested air can alsomake a cleaner of the present invention float, the cleaner may beweighted and balanced such that it immediately points the nose (theportion opposite the thrust jet) down, thereby positioning the thrustjet at the highest point of the cleaner, with the ingested air having nochoice but to migrate to that point along the smooth domed interior.

The thrust jet then may eject the bulk of the ingested air, aided by asmall suction hole through the wall of the thrust tube, sitting at anangle from the highest point of the dome into the thrust tube behind thepropeller. The Venturi principle may be employed to suck out remainingair. The smooth domed nature of the debris-collection chamberadditionally prevents air pockets from accumulating within a cleaner.

Mechanical actions associated with drive and thrust motors and startswitches of the cleaners may avoid penetrating the motor blocks of thecleaners by utilizing magnets. Doing so allows operation of the thrustmotor even when dry. In at least some versions of the invention, a drivemotor may use an array of four magnets on a disk, interfacing linearlywith another disk of four magnets on the other side of a sealed wall. Inthese versions the thrust motor may have four rectangular magnets whichinteract radially (rather than linearly) with magnets on the other sideof a thin-walled tube. This approach eliminates an axial load on theshafts of both the motor and the propeller and provides anenergy-efficient system as compared to a frictional lip seal solution.

The magnet drives also may function as clutches when motive elements orpropellers are stopped or jammed (as by debris, for example). Whereas adirect lip seal drive normally causes a current spike when such jammingoccurs, which may harm batteries or electronics, the magnet drive willnot. Finally, the start switch of a cleaner may be activated internallyby a magnet moving over, e.g., a reed switch on the other side of asealed wall of the motor housing, again preserving the integrity of themotor housing.

It thus is an optional, non-exclusive object of the present invention toprovide cleaning devices for water-containing devices including spaswith complex interior geometries.

It is another optional, non-exclusive object of the present invention toprovide automatic cleaning devices that have positive buoyancy in water.

It is also an optional, non-exclusive object of the present invention toprovide automatic cleaning devices in which down force may be generatedto offset their positive buoyancy.

It is a further optional, non-exclusive object of the present inventionto provide automatic cleaning devices having sloped bottom surfaceswhich are not parallel to to-be-cleaned surfaces.

It is, moreover, an optional, non-exclusive object of the presentinvention to provide automatic cleaning devices in which a (or the)front motive element may be a rotating scrub brush.

It is an additional optional, non-exclusive object of the presentinvention to provide automatic cleaning devices in which a front motiveelement is driven at a different speed than are rear motive elements.

It is yet another optional, non-exclusive object of the presentinvention to provide automatic cleaning devices in which rotating scrubbrushes form walls or boundaries of the water inlets and facilitatelifting of debris into the cleaning devices.

It is an added optional, non-exclusive object of the present inventionto provide automatic cleaning devices in which water is exhausted fromthe devices at acute angles to both the to-be-cleaned surfaces and thesloped bottom surfaces of the cleaners.

It is also an optional, non-exclusive object of the present invention toprovide automatic cleaning devices designed to facilitate removal of airingested into the cleaners.

It is a further optional, non-exclusive object of the present inventionto provide automatic cleaning devices in which magnets may be employedas part of drive and thrust operations of the cleaners.

Other objects, features, and advantages of the present invention will beapparent to persons skilled in the relevant art with reference to theremaining text and the drawings of this application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an automatic cleaner consistent with thepresent invention showing, principally, a nominal front and side of thecleaner.

FIG. 2 is another perspective view of the cleaner of FIG. 1 showing,principally, a nominal rear and side of the cleaner.

FIG. 3 is another perspective view of the cleaner of FIG. 1 showing,principally, a bottom, side, and nominal rear of the cleaner.

FIG. 4 is a bottom plan view of the cleaner of FIG. 1.

FIG. 5 is a side elevational view of the cleaner of FIG. 1.

FIG. 6 is a perspective view of the cleaner of FIG. 1 with a lid of thecleaner opened to expose certain components within the body of thecleaner.

FIG. 7 is a sectioned elevational view of the cleaner of FIG. 1.

FIG. 8 is a perspective view of a male portion of a multi-pin contactcharger for batteries of the cleaner of FIG. 1.

FIG. 9 is a perspective view of a filter for placement within the bodyof the cleaner.

FIG. 10 is a sectioned view of the cleaner of FIG. 1 showing,principally, components of a magnetic drive assembly of the cleaner.

FIG. 11 is another sectioned view of the cleaner of FIG. 1.

DETAILED DESCRIPTION

Illustrated in FIGS. 1-5 is a version of cleaner 10. Cleaner 10preferably is an automatic device, configured to be submerged and travelautonomously within a spa or other water-containing vessel withoutmanual assistance or external cords or cables. Although cleaner 10 maybe sized consistent with the vessel in which it is to operate, preferreddimensions of cleaner 10 may be approximately 216 mm wide, 195 mm long(front to rear), and 182 mm high. If so sized, cleaner 10 may beespecially useful in cleaning recreational and therapeutic spas, whichconventionally are smaller than most swimming pools.

Cleaner 10 also preferably (but not necessarily) is buoyant in water ofa pool or spa. As shown in FIGS. 1-5, cleaner 10 may include body 14,one or more (nominally) front motive elements 18, and one or more(nominally) rear motive elements 22. FIGS. 1 and 4 detail the presenceof two front motive elements 18 in the form of first and secondscrubbers 18A and 18B, respectively. FIGS. 2 and 5 detail the presenceof two rear motive elements 22A and 22B, again respectively.

Rear motive elements 22A and 22B preferably are wheels, with element 22Abeing positioned at or to side 26 of body 14 and element 22B beingpositioned at or to side 30 of body 14. Elements 22A and 22B may beconnected to one or more drive motors and driven either separately ortogether. As best illustrated in FIGS. 2 and 4, elements 22A and 22B maybe aligned such that they rotate about a common axis. The elements 22Aand 22B further may, but typically will not, share a common axle.

Whereas rear motive elements 22 preferably are wheels, front motiveelements 18 preferably are not. Instead, front motive elements 18beneficially may be scrubbers. Nevertheless, scrubbers 18A and 18B maybe connected to one or more drive motors 31 (see FIG. 10) and driveneither separately or together. If two or more elements 18 are present,they advantageously may be aligned such that they rotate about a commonaxis and may, but typically will not, share a common axle.

Also depicted in FIG. 1 are front caps 34A and 34B. Front cap 34A isshown as being positioned adjacent scrubber 18A at or to side 26 of body14, and front cap 34B is positioned adjacent scrubber 18B at or to side30 of the body 14. Body 14 additionally may have a generally dome-shapedlid 38, as illustrated in FIG. 1, which itself may include an exhaustport 42. Persons skilled in the art will recognize that port 42 may belocated elsewhere in connection with cleaner 10, although itspresently-preferred placement is a laterally-central area of the cleaner10 toward or at the nominal rear portion 44 of body 14 (see FIG. 2).

FIG. 1 additionally illustrates a clip and handle assembly 46beneficially located toward or at the nominal front portion 45 of body14. Assembly 46, together with hinges 50 (see FIG. 6), facilitatesopening and closing of lid 38 relative to nominally lower section 54 ofbody 14, with its clip portion either locking lid 38 in place (as inFIG. 1) or allowing it to open (as in FIG. 6). If desired assembly 46also may be constructed to include a handle or similar device allowing aperson to grasp lid 38 and either move it relative to lower section 54or, if lid 38 is locked in place, to move the entirety of cleaner 10from place to place.

Thrust may be provided, at least in part, by jetting water outward fromport 42. FIG. 7 shows propeller 58 placed within body 14 together withthrust-straightening vanes 58A at or near port 42; when operating, thepropeller 58 may push water from within the body 14 to, and out of, port42, hence creating the thrust jet discussed earlier in this application.Propeller 58 and vanes 58A may be part of thrust assembly 62 (see FIG.7), which also may include motor 66 and shaft 70 connecting thepropeller 58 to the motor 66 as well as thrust tube 85. As isconventional, motor 66 operates to rotate shaft 70, in turn rotatingpropeller 58.

Thrust assembly 62 additionally may include magnet assembly 72comprising one or more magnets 73. Employing magnets to effect somemechanical actions may enhance the seal integrity of assembly 62 and bebeneficial by allowing operation of motor 66 even when dry. By contrast,normal lip seals can overheat and be damaged when run dry.

In the version of magnet assembly 72 illustrated in FIG. 7, fourrectangular magnets 73 exists and interact with radially (rather thanlinearly) with magnet on the other side of a thin-walled tube withinbody 14. This configuration eliminates axial loads on shaft 70 and isparticularly energy-efficient as compared with conventional lip-sealapproaches. Magnets 73 may differ in number, shape, and placement,however, as is necessary or desired. Finally, magnet assembly 72 mayalso function as a clutch should, for example, propeller 58 be jammed orhave its rotation stopped by debris. Again, by contrast, such jammingwould be detrimental to direct lip-seal drives, normally causing currentspikes capable of harming batteries and electronics.

FIG. 7 depicts nominal forward direction of movement “A” of cleaner 10along a to-be-cleaned surface “B.” Thrust assembly 62 exhaustspressurized water out port 42 in direction “C,” which forms an acuteangle α₁ with surface B and an obtuse angle α₂ with vector A. (This canbe readily contrasted with, for example, the cleaners of the Huiapplication, in which the angles corresponding to α₁ and α₂ would bothbe right angles.) A presently-preferred value for angle α₁ isapproximately sixty degrees (˜60°), which continues to allow theexhausted water to provide substantial down force to cleaner 10. Personsskilled in the art will recognize that other values less than ninetydegrees (<90°) may be acceptable as well.

Inlet port 74 appears in FIG. 7. Port 74 leads to inlet section 78 offilter 82 within body 14. Clear from FIG. 7 is that port 74 may beadjacent front motive elements 18, positioned immediately behind theelements 18 relative to the normal direction of travel A. Motiveelements 18 hence may be considered to be within or inside port 74 or toform a wall or boundary thereof. Counterclockwise rotation of elements18 thus serves not only to agitate debris into suspension, but also toaccelerate and “paddle” the debris mechanically into inlet port 74 andinlet section 78 of the filter 82.

So positioning port 74 leads to efficient movement of debris-laden waterinto filter 82 within body 14. However, it also increases the likelihoodof cleaner 10 ingesting air, particularly when the cleaner 10 is onlypartially submerged while scrubbing a wall or similar surface at thewaterline of a vessel. Introducing air into a water-pumping system canbe detrimental for multiple reasons, including causing a pump motor torun dry and the associated cleaner to float away from the surface to becleaned. To reduce these detrimental aspects of air ingestion, cleaner10 may be weighted and balanced such it immediately points front portion45 downward, thereby positioning port 42 (and therefore the exhaust frombody 14) at the highest point of the cleaner 10. Because lid 38 isshaped as a dome with a generally smooth interior surface, ingested airhence must migrate within lid 38 to that highest point, where it too canbe expelled.

Indeed, because motor 66 may continue operating even when air isingested, it may eject most of the ingested air through port 42. Thisejection may be aided by opening 84, a small suction hole in a wall ofthrust tube 85 angled from the highest point of lid 38. Utilizing theVenturi principle, fluid flowing out port 42 may cause ingested air tobe evacuated from body 14 through opening 84 and out port 42.

Rear portion 44 of body 14 may include interface 86 useful to charge oneor more batteries within the body 14 powering the various motors. In atleast one version of body 14, interface 86 may be a female portion of amulti-pin contact charger. FIG. 8 illustrates a corresponding maleportion 90 of the charger. Portion 90 may self-latch to interface 86using magnets. In the five-pin embodiment of portion 90 depicted in FIG.8, which may be reversible left to right, connection of center pin 94 toa corresponding center opening of interface 86 may signal that thecharger is operational. Once certain pin 94 is removed, power to theother four pins is withdrawn so as to avoid power leaking into the waterof the vessel.

At present, lithium iron (LFP) batteries are preferred for use as partof cleaner 10. Their charge statuses may be monitored during operationof cleaner 10 and, if desired, energy to the various motors may beincreased as the batteries are exhausted so as to maintain approximatelyconstant performance of cleaner 10 during a cleaning cycle. One or morelight emitting diodes or other devices may indicate performance statusesof the cleaner 10.

FIGS. 3-4 depict sensor 98 present on bottom surface 102 of body 14.Sensor 98 may be designed to ascertain whether body 14 is immersed inwater, sensing conductivity changes between its two metallic posts 206due to the presence, or absence, of water. A well 210 may circumscribeeach post 206 and contain wax so as to enhance reliability of thesensing. Preferably, when sensor 98 does not detect the presence ofwater, power to the various motors of cleaner 10 will be withdrawnimmediately. Sensor 98 also, if desired, may function together with amagnetic start switch 214; if the start switch 214 is “on” and sensor 98detects that cleaner 10 is in water, power will be provided to themotors of the cleaner 10.

Among significant features of cleaner 10 is that bottom surface 102 issloped relative to a to-be-cleaned surface such as surface B of FIG. 7.As illustrated in that figure, bottom surface 102 thus may form an angleα₃ with surface B rather than be parallel thereto (as in the cleaners ofthe Hui application, for example). One presently-preferred value forangle α₃ is approximately twenty degrees (˜20°), although other valuesmay be satisfactory as well.

Bottom surface 102, furthermore, may be closest to surface B at frontportion 45 (adjacent inlet port 74) and farther from surface B at rearportion 44. The increased distance between bottom surface 102 andsurface B toward rear portion 44 materially minimizes, if not whollyprevents, high centering of cleaner 10 otherwise possibly caused by acleaner encountering an obstacle protruding from surface B anddisengaging all driven motive elements from the surface B.

Scrubbers 18A-B preferably are driven at a higher speed than are rearwheels 22A-B, with an exemplary (but not exclusive) speed ratio beingapproximately 1.3:1. Driving scrubbers 18A-B at a higher speed allowsthem to scrub a surface (such as surface B) as they rotate whileconcurrently helping cleaner 10 travel along the surface. This approachmay be contrasted with that of conventional cleaners, which typicallydrive their motive elements at the same rotational speed.

Collectively, scrubbers 18A-B may extend more or less completely acrossthe width of body 14. The angling of bottom surface 102 (α₃) and theexhausted water (α₂) effectively move the high-centering point ofcleaner 10 near the scrubbers 18A-B. However, because scrubbers 18A-Bare motive elements, they may drive cleaner 10 (effectively leveringfront portion 45) over obstacles. If desired to facilitate turning ofcleaner 10, scrubber 18A may always be driven in the same direction(clockwise or counterclockwise) as its corresponding wheel 22A, andscrubber 18B may be driven in the same direction as wheel 22B, butscrubber 18A/wheel 22A need not always be driven in the same directionas scrubber 18B/wheel 22B.

Each scrubber 18A or 18B may comprise core 106 and extensions 110. Core106 typically will be cylindrically shaped with a central longitudinalbore or annulus for receiving an axle 112. The axle 112, in turn, can bedirectly or indirectly connected to a motor of cleaner 10 so as torotate it. Extensions 110 may, if desired, be in the form of bladesprotruding from, and spaced along, the circumference of core 106. Ingeneral, at least extensions 110 have substantial flexibility. Caps34A-B may function to protect the drive mechanism of scrubbers 18A-Bfrom contact with certain features of spas or pools and to preventhigh-centering of that mechanism. Because caps 34A-B may protrude beyondthe nominal width of body 14, they additionally may facilitate brushingand cleaning of, e.g., corners of pools and spas. FIG. 11, further,shows that axle 112 may extend beyond scrubbers 18A and 18B for use inrotating caps 34A-B as well.

An exemplary filter 82 is illustrated in FIG. 9. A preferred filter 82fits within body 14 between bottom surface 102 and lid 38 in a manner sothat debris-laden water entering inlet port 74 must encounter it beforeexiting via exhaust port 42. As shown in FIG. 9, filter 82 may comprisemesh 114 supported by frame 118. Most particulate debris suspended inwater entering port 74 will be stopped (blocked) by mesh 114,mechanically cleaning the water as it passes through the filter 82.Filter 82 advantageously is removable from body 14 for emptying debrisand cleaning and, if desired, may have frame 118 made of two parts, onehinged or otherwise movably connected to the other so as to allow theframe 118 to open and expose debris therein.

Depicted in FIG. 10 are components of a drive motor assembly 122. Twosuch assemblies 122 preferably are present in cleaner 10, although moreor fewer may be included as desired. As shown in FIG. 10, an assembly122 may include motor 31, magnet drive 126, and gear drive 130. Magnetdrive 126 may include a first array of magnets 134 on a disc, with themagnets 134 interfacing linearly with another disc of magnets 138opposite a sealed wall 142. As with magnet assembly 72, magnet drive 126may avoid use of lip seals, as no shaft need penetrate wall 142, andfunction as a clutch should motive elements 18, for example, becomejammed.

The foregoing is provided for purposes of illustrating, explaining, anddescribing embodiments of the present invention. Modifications andadaptations to these embodiments will be apparent to those skilled inthe art and may be made without departing from the scope or spirit ofthe invention. As but one example, cleaner 10 may be adapted to receivecontrol signals from a remote source (e.g. a wireless transmitter, astypically exists in a smartphone) capable of controlling aspects ofoperation of the cleaner 10. Such control signals could, for example,change speed or rotation direction of any or all of motive elements 18or 22 (or disable their drives) or inhibit or change operationalcharacteristics of thrust assembly 62. Cleaner 10 may also be adapted totransmit information about its operation or the water within the vesselto a location remote therefrom. As yet another example, cleaner 10 mayinclude an on-board processor and memory for creation and storage ofcontrol information or data (or both), whether or not such informationor data is transmitted to or received from a remote source of location.

1.-7. (canceled)
 8. An automatic cleaner for a water-containing vessel,comprising: a. a body comprising an inlet and an outlet; b. means formoving the body along a surface of the vessel; and c. a magnet drive (i)connected to the body-moving means and (ii) comprising a wall and atleast one magnet positioned on each side of the wall.
 9. An automaticcleaner according to claim 8 in which the wall is sealed from ingress ofwater from the vessel.
 10. An automatic cleaner according to claim 9 inwhich the at least one magnet positioned on each side of the wallcomprises an array of magnets on a disc positioned on each side of thewall.
 11. An automatic cleaner according to claim 10 in which thebody-moving means comprises a motive element and a propeller and inwhich the magnet drive functions as a clutch when the motive element orthe propeller is jammed in use.